1. Field of the Invention
The present invention relates to an image processing system. More specifically, the present invention provides a system for adjusting a video signal to compensate for a camera that is offset from an object of a captured image.
2. Background
Various types of image processing systems, such as video conferencing systems, utilize a camera coupled to a computer or other image processing system to capture an image of an object, such as the person or persons participating in the video conference. The image processing system is capable of storing, displaying, or transmitting the captured image. For example, in a video conferencing system, the image processing system transmits the captured image to a similar image processing system at the opposite end of a video conference link.
Personal video conferencing systems may be utilized when a single participant is located at each end of the video conference link. Personal video conferencing systems typically utilize a camera mounted to a computer monitor. The camera may be mounted on top of the computer monitor or on either side of the monitor. Generally, the conference participant sits in front of the monitor, which displays an image of the other conference participant. In a personal video conferencing system, the conference participants are typically located close to the computer monitor and close to the camera. Since the camera is not located directly in front of the conference participant, the camera is typically aimed toward the participant.
For example, if the camera is mounted on top of the computer monitor, the camera is aimed down toward the face of the conference participant. Similarly, if the camera is mounted on the side of the computer monitor, then the camera is aimed inward toward the conference participant. Since the aiming axis of the camera is offset from the natural, face-to-face viewing angle, the image of the conference participant is distorted. The offset camera causes expansion of the portions of the captured image closest to the camera (e.g., the conference participant's forehead). The offset camera also causes compression of portions of the captured image farthest from the camera (e.g., the participant's mouth and chin).
The distortion of the conference participant produces an unnatural image that is transmitted to the other conference participant. The unnatural image reduces the overall quality and realism of the conferencing system.
Therefore, it is desirable to provide a system that compensates for an offset camera in a video conferencing system.